Coanda gas burner apparatus and methods

Abstract

A gas burner apparatus for discharging a mixture of fuel gas, air and flue gas into a furnace space of a furnace wherein the mixture is burned and flue gas having a low content of nitrous oxides and carbon monoxide is formed is provided. The burner tile includes at least one gas circulation port extending though the wall of the tile. The interior surface of the wall of the tile includes a Coanda surface. Fuel gas and / or flue gas conducted through the gas circulation port follows the path of the Coanda surface which allows more flue gas to be introduced into the stream. The exterior surface of the wall of the tile also includes a Coanda surface for facilitating the creation of a staged combustion zone. Also provided are improved burner tiles, improved gas tips and methods of burning a mixture of air, fuel gas and flue gas in a furnace space.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to gas burner apparatus and methods of burning fuel gas in the presence of air and furnace flue gas to create a stable flame while suppressing the formation of nitrous oxides (“NOx”) and carbon monoxide (“CO”).[0002]Various types of gas burners have been developed and successfully utilized with a combination of both diffusion and pre-mix capabilities. A pre-mix approach mixes both the air and fuel gas to a homogenous mixture prior to combustion within the confines of the furnace. A diffusion approach injects the fuel gas into an air stream wherein mixing takes place without a venturi. The flame is stabilized close to the point of exit, creating both thermal and prompt nitrous oxides. Both approaches are routinely utilized to ignite and combust a given fuel gas to generate heat within a process burner.[0003]In both pre-mix and diffusion-type burners, an optimum approach can be defined to reduce both thermal and prompt nit...

AI Technical Summary

Benefits of technology

The present invention provides a gas burner apparatus and methods that meet the needs of reducing nitrous oxides and carbon monoxide emissions in a furnace. The invention uses a Coanda surface to mix fuel gas with air and flue gas, resulting in a more stable flame and improved heat distribution. The Coanda surface allows for increased amounts of flue gas to be incorporated into the mixing and combustion zones without diluting the fuel gas. The invention also includes a plenum and various methods for injecting fuel gas and air into the burner. The use of a Coanda surface and a pre-mix unit allows for a more complete mixing of the fuel gas and air, resulting in a more efficient flame and better heat distribution. The invention also provides a secondary fuel gas injection means for injecting fuel gas from outside the burner tile, allowing for greater control and stability of the flame. Overall, the invention improves the performance and stability of gas burners in furnaces.

Problems solved by technology

However, if the fuel gas is overly diluted, it may be difficult to ignite or the ignited flame may become unstable.

However, Coanda surfaces have not been incorporated into low NOX process burner apparatus.

As a result, Coanda technology has not been actively applied to process burners.

Also, many refinery operators have not changed the refinery furnaces due to the expense involved therewith.

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